The Liberty Gazette
November 11, 2014Ely Air Lines
By Mike Ely and Linda Street-Ely
Linda: A few years ago as the City of Liberty was struggling with how best to develop our airport one of the first things that had to be done was bring up to date the zoning around the airport before any more grants would be given. This zoning is known as height hazard zoning and is not what you think of when you think of land zoning. This is regulated by the FAA and is a requirement for any airport that accepts federal money, as Liberty does.
Liberty County and the cities of Liberty and Ames created a height hazard zoning board in order to comply with these regulations and to be eligible to receive further federal grant money. TxDOT, under authority of the FAA, performed a height hazard study and the board accepted the study. Then each of the governmental entities voted to accept those zoning regulations. This effectively keeps someone from placing a cell tower or windmill so close to the airport as to create a hazard to aircraft.
Under these rules, on an airport the size of Liberty’s no structure may be built within 250 of the outer edges of the runway. At large airports such as Bush Intercontinental, the required distance expands to 400 feet. There are exceptions for structures in existence prior to the ordinance, however those structures must be lighted so pilots can see them. You can imagine the danger to a pilot and to people on the ground if a structure violates safety zoned air space and isn’t even lighted. Once on notice both the owner of the structure and the city may be held liable.
Mike: And what if a pilot is flying in soupy weather? Flying "on instruments" is the kind of flying necessary when visibility is so poor that a pilot can’t see through the clouds or fog. An approach to land at an airport may be either visual or instrument. If it’s an instrument approach, meaning published procedures are used that safely get an airplane to the runway in poor conditions, you can bet that hazardous structures need to be even farther away, just in case a plane is a little bit off course. For that reason, in order for an airport to increase safety with instrument approaches there must be a larger safety zone. Approval of safety enhancing instrument approaches are dramatically affected by the existence of hazardous structures.
From the 250’ (or 400’) point the protected area extends outward and upward at a specific angle for several miles. Buildings, antennas, windmills, cannot be built to encroach on this protected air space. The angle off each end of the runway is even more restrictive because that’s where airplanes are closer to the ground – taking off and landing.
As Liberty proceeds through the process of extending the runway, height hazard zoning will be revisited under the leadership of the helpful people from TxDOT.
The FAA has reviewed its criteria for height hazards and will tighten up restrictions, making protected zones larger, setting stricter height limitations for structures near airports.
This move, applauded by pilots and the managers and owners of airports, means increased safety zones for the people who use airports as well as people on the ground.
Why would anyone build a house under the approach path to an airport anyway? Local ordinances and height hazard zoning help prevent this from happening and promote safety.